Briggs and Stratton Stuck Exhaust Bolt

[css9343]

I recently acquired a free Toro Timemaster 30 inch with a Briggs 121S17-0127-F1 and I'm attempting to get it running. It had a blown head gasket, and in taking off the cylinder head one of the muffler bolts snapped. I've tried everything to get it out and I'm just about out of ideas. Here's what I've tried.

An entire bottle of pb blaster (not literally but a ton)

Filing down flat edges on the stub and rocking vice grips back and forth on it. Just mushed the metal right off the bolt.

Drilling out the bolt and hammering a torx bit in the opening. I've seen folks do this with great success. My torx bit snapped off in the bolt.

Grinding head on a Dremel to grind out the torx bit inside the bolt. Just melted the bit.

Next idea would be to grind a slit in the bolt and flathead it out, or try and tackweld a flathead to the top of the bolt and rock it out.

1. Any ideas or suggestions?

2. Do I actually need two bolts on a muffler?

3. Are there replacement mufflers I could use?

Really trying to avoid the $100 to buy a new cylinder head but also don't want to spend $$$ only to have to turn around and buy the head anyway.

 

[Hammermechanicman]

Sounds buggared up pretty good by now. I would drill it out.

 

[StarTech]

yes it will need drilling out but most HHS bits will only dull attempting it. Get yourself one those carbide tip concrete drill bit and drill out the remaining bolt. Then either tap it if possible or drill out for a Heli coil, tap it, and install a Heli coil.

There bolts are usually heat seized and heat harden. Carbide bits are the only thing I found to work reliably for removal.once the bolt is broken off. I even broke extractor off trying to remove these bolts and carbide is the only thing that will cut the extractor out.

 

[Hammermechanicman]

I use good cobalt drills from tool supply house. Not the harbor freight ones.

 

[StarTech]

Now now Hammer you HFT got the best bits. Even those I got years ago from Lowes were junk. Currently using Fastenal bits here for most of my drill along the Drill Dctor for resharpening. Just drill out 18 broken tri lobe screw and only broke one bit.

 

[Hammermechanicman]

I have a couple indexes of the HF twist drills. I consider them as consumables. I have a drill doctor 750x and good to go with the HF twist drills to be used and abused. I have some good left hand twist drills and some good regular twist drills i reserve for precision work with the drill press. I have to sharpen the HF twist drills before i use them so i don't get the 3 sided holes.

 

[Hammermechanicman]

If he snapped off a muffler bolt it is seized in the head it won't twist out with a left hand drill. Been there done that, many times.

 

[mechanic mark]

https://www.lowes.com/pd/DEWALT-14-Piece-Cobalt-Twist-Drill-Bit/50413714

My choice for quality.
Use reversible drill with left hand drill bits. Start small going slow with light pressure on drill & oil bit frequently to keep it cool.
Let us know how it goes, thanks, Mark

left hand drill bits - Google Search

 

[bertsmobile1]

There is an engineering workshop down the road with a water jet drill
$ 20 and job done in 5 minutes, all that is left is the spiral of thread of the old stud / bolt
Now if I had a lazy $ 30,000 ?
If we have em down here in the bannana republic they must be on every street corner in the USA .
We spent around 100 hours removing a broken head stud in an Inter 445, only to find the machine shop could have come out with their mobile kit and removed in for $ 90 in 15 minutes.

 

[Hammermechanicman]

You can't do it on an aluminum head but in cast iron i can use an oxy torch to blow a broken stud out of a blind hole and leave the threads intact.